Dispenser mixing module and method of assembling and using same

ABSTRACT

A mixing module that includes a mixing chamber formed of a cold flow material and placed within a housing which includes a compression device for compressing the cold flow material through which extends a reciprocating rod, preferably in the form of a valve rod relative to one or more chemical ports formed in the mixing chamber to mix or deliver chemicals within a mixing reception recess. The mixing chamber features a locking arrangement between the cold flow material mixing chamber and the housing which acts to prevent movement of the mixing chamber within the housing due to a sticking of the reciprocating rod to the mixing chamber which otherwise produces a position change in the mixing chamber as the compression device is temporarily compressed until the rod be comes unstuck and releases. The invention also includes an open front and rear end housing with releasable front and rear caps allowing easy insertion of the mixing chamber preferably having an annular front end rim as the locking member for receipt within a corresponding recess in the housing.

CROSS-REFERENCE TO PRIORITY APPLICATIONS

The present invention is a divisional of U.S. application Ser. No.10/623,716, filed Jul. 22, 2003, which claims priority under 35 U.S.C.§119(e) to U.S. Provisional Application No. 60/468,942 filed on May 9,2003 and U.S. Provisional Application No. 60/469,038 filed on May 9,2003, and each of the above identified applications are incorporatedherein by reference in their entirety.

FIELD OF THE INVENTION

The present invention is directed at a method and apparatus fordispensing material such as foam for use in, for example, the formationof foam cushion bags or in a more direct application of the dispensedfoam, as in a foam in place packaging protection process or injection offoam material within a confined area such as in an insulation injectionprocess.

BACKGROUND OF THE INVENTION

Over the years a variety of material dispensers have been developedincluding those directed at dispensing foamable material such asurethane foam. For example, when certain chemicals are mixed togetherthey form polymeric products while at the same time generating gasessuch as carbon dioxide and water vapor. If those chemicals are selectedso that they harden following the generation of, for example, carbondioxide and water vapor, they can be used to form “hardened” (e.g., acushionable quality in a proper fully expanded state) polymer foams inwhich the mechanical foaming action is caused by the gaseous carbondioxide and water vapor leaving the mixture.

In some techniques, synthetic foams are formed from liquid organicresins and polyisocyanates in a mixing chamber (e.g., a liquid form ofisocyanate, which is often referenced in the industry as chemical “A”,and a multi-component liquid blend such as one including polyurethaneresin for producing polyurethane foam, which is often referenced in theindustry as chemical “B”). The mixture can be dispensed into areceptacle, as in a package or a foam in place bag (see e.g., U.S. Pat.Nos. 4,674,268, 4,800,708 and 4,854,109 which are incorporated byreference), where it reacts to form the foam.

A particular problem associated with certain foams as in polyurethanefoams is that once mixed, the organic resin and polyisocyanate generallyreact relatively rapidly so that the resultant foam product tends toaccumulate in all openings through which it passes, including a backingup of foam into openings through which the components passed beforemixing. Furthermore, some of the more useful polymers that form foamablecompositions are adhesive. As a result, the foamable composition, whichis often dispensed as a somewhat viscous liquid, tends to adhere toobjects that it strikes and then harden in place. Many of these adhesivefoamable compositions tenaciously stick to the contact surface makingremoval particularly difficult.

Solvents are often utilized in an effort to remove the hardened foamablecomposition from surfaces not intended for contact, but even withsolvents (particularly when considering the limitations on the type ofsolvents suited for worker contact or exposure) this can prove to be adifficult task. The undesirable adhesion can take place in the generalregion where chemicals A and B first come in contact (e.g., a dispensermixing chamber) or an upstream location as in individual injection portsin light of the expansive quality of the mix, or downstream such as adispensing gun or, in actuality, anywhere in the vicinity of thedispensing device upon, for instance, a misaiming, misapplication orleak (e.g., a foam bag with leaking end or edge seal). For example, a“foam-up” in a bag dispenser, where the mixed material is not properlyconfined within a receiving bag, can lead to foam hardening in everynook and cranny of the dispensing system making complete removal notreasonably attainable particularly when considering the configuration ofthe prior art systems. A misdirected stream from a hand held gun outletcan also end up covering numerous unwanted surfaces.

Because of this adhesive characteristic, steps have been taken in theprior art to attempt to preclude contact of chemicals A and B atnon-desired locations as well as precluding the passage of mixedchemicals A/B from traveling to undesired areas or from dwelling inareas such as the discharge passageway used in aiming the A/B chemicalmixture. Examples of injection systems for such foamable compositionsand their operation are described in U.S. Pat. Nos. 4,568,003 and4,898,327, and incorporated entirely herein by reference. As set forthin both of these patents, in a typical dispensing cartridge, the mixingchamber for the foam precursors is a cylindrical core having a bore thatextends longitudinally there through. The core is typically formed froma fluorinated hydrocarbon polymer such as polytetrafluoroethylene(“PTFE” or “TFE”), fluorinated ethylene propylene (“FEP”) orperfluoroalkoxy (“PFA”). Polymers of this type are widely available fromseveral companies, and one of the most familiar designations for suchmaterials is “Teflon”, the trademark used by DuPont for such materials.For the sake of convenience and familiarity, such materials will bereferred to herein as “Teflon”, although it will be understood that thematerials available from companies other than DuPont and of other typescan also be used if otherwise appropriate.

In the aforementioned systems, a plurality of openings (usually two) arearranged in the core in communication with the bore for supplying theorganic resin and polyisocyanate to the bore, which acts as a mixingchamber. A combination valving and purge rod is positioned to slide in aclose tolerance, “interference”, fit within the bore or mixing chamberto control the flow of organic resin and polyisocyanate from theopenings into the bore and the subsequent discharge of the foam from thecartridge.

With hand held and foam-in-bag dispensing apparatus there is typicallyprovided chemicals A/B from their respective sources (typically a largecontainer such as a 55 gallon drum for each respective chemical) in thedesired state (e.g., the desired flow rate, volume, pressure, andtemperature). Thus, even with a brand new dispenser, there areadditional requirements involved in attempting to achieve a desired foamproduct. Under the present state of the art a variety of pumpingtechniques have arisen as in individual pumps designed for insertiondirectly into the chemical source containers coupled with a controllerprovided in an effort to maintain the desired flow rate characteristicsthrough pump control.

FIG. 1 illustrates an (electric) hand held two component prior artdispensing system 20. System 20 includes chemical drums 22, 24 for thetwo chemical components “A” and “B” to be mixed to produce a dispensedfoam. Pumps 26, 28 extend within the drums “A” and “B” each pump havinga combination tachometer and a DC motor set (27, 29). Pumps 26, 28 areeach wired to control console 30. Chemical conduits 32, 34 extend fromthe pumps, through hanging support structure 36 and are connected tohand held dispenser 38. Heater wire coils are present in each ofconduits 32, 34, to control chemical temperature, and electric lines 31,33 extend from the control console and into electrical connection withthe heater wire coils in the conduits. Electric line 35 extends from thecontrol console to the electric valve rod reciprocation motor of thedispenser. Adjacent dispenser 38, there is positioned stand 40 forsupporting box 42 and a dispenser holster 44. Dispensing system 20 is aclosed loop control system with positive displacement pumps whichattempt to maintain “on ratio” delivery for every dispenser “shot”activation by continuously monitoring and adjusting temperature,pressure and pump speed.

FIG. 2 provides an exploded view of prior art hand held dispenser 38which comprises handle 46 having hand grasp extension 48 and mountingbase 50 supporting valve rod reciprocation motor 52, mixing cartridge“below” carrier 54 and mixing cartridge “upper” carrier 56. Carriers 54and 56 are design to retain in position mixing cartridge assembly 58.Lower carrier 54 also functions as a manifold for chemicals received viahose adaptor fittings 60, 62 and receives valve control plugs 64, 66,filter assemblies 68, 70, and O-rings 71, 73 for avoiding chemicalleakage between the lower carrier outlet (72 one shown) and cartridgeassembly's housing ports (74—one shown). Chemical mixing cartridge 58 isclamped between lower carrier 54 and upper carrier 56, which are securedtogether by fasteners 76, while cartridge position fixation screws 78extend into fixing cavities 80, in 80′ cartridge assembly 58.

FIGS. 3A and 3B provide an illustration of the interior of prior artmixing cartridge assembly 58 (see U.S. Pat. No. 4,898,327 sharingsimilarities with that shown in FIG. 2. As shown, the prior artcartridge assembly 58 includes housing 82 with accessible rear end 84(C-Clip), apertured front end 86, Teflon mixing chamber 88 which defineschemical mixing area 89 (the actual “mixing chamber”), chemical A and Bmixing chemical port members 90, 92 (FIG. 3B) receiving chemical fromhousing port inlets 91, 93, and valve rod 94. In an effort to maintain asealing relationship with the valve rod, Belleville washer stack 96pushes against the intermediate disk 98 to maintain the Teflon materialcompressed. After packing, the open rear end is closed by way of aspecial pressing tool (not shown) which allows for the end cap 91 andclip 84 to be positioned.

Despite a great deal of effort in the art (e.g., see, for example, U.S.Pat. Nos. 4,469,251; 4,867,346; 5,211,311; 5,090,814; 5,180,082;5,709,317) the prior art mixing cartridges need to be serviced andreplaced with a great deal of frequency causing a corresponding largeamount of wasteful operator down time and operator frustration.

In these prior art devices the actual mixing takes place in thecylindrical hole or cavity that is drilled through the central axis ofthe Teflon cylinder. Thus, the mixing region chamber is actually a holesurrounded by the inside diameter of the relatively thick walled Tefloncylinder (it is noted that the term “mixing chamber” is often used inthe art in a broader sense, to include the chamber forming structure).The cavity or bore is where both urethane components A and B impinge,mix, and start the reaction process that creates foam.

Functional prior art foam-dispensers that employ a Teflon mixing chambersuch as those listed above are customarily made from various grades ofTeflon, because of its superior non-stick properties. The mixingchambers such as those in the patents noted above are generallycylindrical in shape and compressed against the front of the housing.Desirable features of a mixing chamber in most settings include, (i)maximizing mixing efficiency; (ii) providing a laminar output stream;(iii) providing leak free valving in the chemical flow.

The mixing chambers of the prior art are generally designed to providemechanical support to impingement ports used to aim the chemical beingejected. One purpose of these chemical ports is to focus the flow ofliquid precursors for high impingement velocity in an effort to enhanceefficiency. The nozzles that the chemicals pass through just prior toentering the mixing chamber itself are commonly called ports in theindustry. These ports help to minimize the cross-sectional area of theoutput jet, maximizing flow velocity, and thereby maximizing impingementpressure when the two streams collide. The exit diameter of the portnozzle opening is designed in these systems with an understanding theopening should not to be smaller than the pressure output capacity ofthe pumping system (e.g., 200 to 300 psi range which might be deemed acomfortable operational level, with a 400 to 500 psi range beingrepresentative of a practical prior art system maximized pressurelevel). Mixing can possibly be enhanced by using additional mechanicalmixing elements in the system, but these can add significant complexityto the design, which can often outweigh any possible mixing advantage.

For greater efficiency (and foam quality), maintenance of both portsclean and unobstructed allows for retention of initial productionsettings. Maintaining the ports properly aligned to impinge at thedesired location as in the centerline of the mixing chamber is alsogenerally considered as being desirable under the prior art systems.

With respect to a laminar output stream, the length of the mixingchamber channel provides a means of damping the turbulence of thechemical flow immediately after impingement. If the turbulence isproperly damped there is provided a laminar quality to the flow of(mixed) chemical that exits the reception (mixing) chamber. A laminaroutput flow, commonly called a “pencil pour”, is easier to aim and muchcleaner to work with than a turbulent or spinning output stream. If themixing chamber length to diameter ratio is too small, however, theoutput stream can be highly erratic. This can be messy for the operator,and is an indication that the chemicals are badly mixed.

Also, it is generally believed in the industry that mixing can beimproved in systems having a longer dwell time in the confines of amixing chamber as the confinement helps keep the chemical components inclose proximity for a longer time. On the other hand, if the mixingchamber is too long, the axial force required to retract the valving rodincreases significantly, resulting in an increase in the size and weightof the associated drive mechanism. High weights and large sizerequirement are generally unacceptable for practical application in, forexample, hand held packaging systems (e.g., the weight of a hand helddispenser needs to be maintained low for user comfort).

Another source for the development of a non-laminar or erratic flow inprior art systems is having the chemicals not impinge at the geometriccenterline of the mixing chamber inside diameter, in that rotationalmomentum can be imparted to the flow stream in the aforementioned priorart systems. This rotational momentum can manifest itself in a spinningof the output stream, which appears as a spray pattern and can causevarious problems.

The mixing chamber in most systems also provides a means for the valvingrod to shut off the flow of liquid precursors and to open up to allowflow and mixing to occur. Thus, an effort is made in prior art systemsto maintain valve arrangements that avoid the formation of highlyproblematic leak paths that can allow the A chemical to mix with the Bchemical at undesirable times and locations. Since Teflon is a marginalsealing material, however, it is quite difficult to provide thenecessary sealing in the pressure range of typical interest (e.g., 200to 500 psi). Compression of the Teflon can potentially improve itsfunction as a seal. For example, compression with a psi loading three tofour times greater than the fluid pressure being sealed. A stack ofBelleville washer at the back of the housing has been used to providethis load.

Also, Teflon seals have the potential for improving with time underload, as over time the Teflon material can cold-flow into themicroscopic surface imperfections that are potential leak paths alongthe face of a sealing surface. Teflon material has more cold-flowtendency than most other engineering plastics because the polymerstrings that comprise the material do not stick to each other. Becauseof this, areas of Teflon material are free to slide past each other, toan extent greater then most other engineering plastics, making Teflonmaterial a useful non-stick surface.

While this cold flow distortion of the Teflon can be beneficial (e.g.,allowing for the conformance of material about surfaces intended to besealed off) it is also a cause of several problems, including thepotential for the loss of the fit between the bore and the valving rodas well as the fit between the openings (e.g., ports) through which theseparate precursors enter the bore for mixing and then dispensing. Inmany of the prior art systems utilizing Teflon, the Teflon core isfitted in the cartridge under a certain degree of stress in order tohelp prevent leaks in a manner in which a gasket is fitted under stressfor the same purpose. This stress also encourages the Teflon to creepinto any gaps or other openings that may be adjacent to it which can beeither good or bad depending on the movement and what surface is beingcontacted or discontinued from contact in view of the cold flow.

Under these prior art systems, however, over time the sealing quality ofthe core is lost at least to some extent allowing for an initial buildup of the hardenable material which can lead to a cycle of sealdegradation and worsening build up of hardened material. This in turncan lead to a variety of problems including the partial blockage ofchemical inlet ports so as to alter the desired flow mix and degrade thequality of foam produced. In other words, in typical injectioncartridges the separate foam precursors enter the bore through separateentry ports. Polyurethane foam tends to build up at the area at whichthe precursor exits the port and enters the mixing chamber. Suchbuildups cause spraying in the output stream, and dispensing of themixture in an improper ratio. The build up of hardened material can alsolead to partial blockage of the dispenser's exit outlet causing amisaiming of the dispensed flow into contact with an undesirable surface(e.g. the operator or various nooks and crannies in the dispenser).

The build-up of hardened/adhesive material over time leads to additionalproblems such as the valve rod becoming so adhered within its region ofseal/no-seal reciprocal travel that either the driver mechanism isunable to move the rod (leading to an oft seen shut down signalgeneration in many common prior art systems) or a component along thedrive train breaks off which is often the valve rod engagement locationrelative to some prior art designs. Moreover, if the Teflon sealingelement is forced to move after it has set at a given position, thequality of sealing, as explained in greater detail below, will bedegraded until the Teflon can re-set in the new position.

A disruption of any of the above mixing chamber functions willnecessitate service or replacement of the mixing module, with resultantdowntime, inconvenience, and expense. Anything that can eliminate orreduce the occurrence of these problems will greatly enhance thereliability of the mixing module.

As a result of studying the aforementioned problems and difficultiesassociated with the prior art, the inventors have come to the beliefthat a source of many of the difficulties and problems associated withthe prior art devices is the tendency for the mixing chamber to movewithin the mixing chamber housing. A review has thus been made under thepresent invention as to the tendency for the chamber to “move around”within the confining cylinder of the mixing chamber housing. The effectsof this movement has been observed by the changes in the position of thestainless steel chemical ports of prior art devices (e.g., by lookingthrough the two flow holes that are drilled radially through the outermetal housing). These housing inlet holes provide a clear view of thechemical ports that are located radially in the body of the Teflonmixing chamber. It has been observed that after a few thousand cycles,the ports will usually rotate noticeably with respect to the mixingchamber housing inlet holes and that the shifting tends to get worsewith more cycles. This movement problem has been determined to manifestitself in mixing chamber movements in both an axial and a radialdirection.

Some examples of the problems considered to exist as a result in theshifting of the mixing chamber within its housing unit, include:

I. Movement of Chemical Ports from Ideal Position

-   -   a. Shifting of the mixing chamber, even by a small increment,        causing the ports to move out of their ideal (as designed and        assembled) position.    -   b. If the A and/or B chemicals ports move out a desired        impingement position, foam quality can be affected.    -   c. The output stream of reacted chemicals from the exit of the        mixing module may spray due to a rotation in the output stream        caused by the ports being out of position.    -   d. If the rotation is severe, the ports can move to a position        so far out of alignment with the flow holes in the housing, that        the flow of chemical can be severely restricted, and system        shutdown will result.

II. Chemical Leakage

-   -   a. Shifting of the mixing chamber, even by a small increment,        can seriously degrade its sealing ability, causing leaks of A        and/or B chemical to locations where they can mix and react with        each other and cause various problems.    -   b. Leaks that cause urethane deposits near the exit areas of the        chemical ports can cause the output stream of the mixing module        to spray, or even total flow blockage.    -   c. If a leak is large enough, it can lead to what is known as a        massive crossover, where large amounts of urethane are produced        in the A and/or B-sides of the dispenser manifold. Massive        crossover in a dispenser manifold are difficult to clean, and        often result in the replacement of many expensive components.    -   d. Chemical leaks can also cause the valving rod to bond to the        mixing chamber. The urethane that forms on the inside diameter        of the mixing chamber over time will have a tendency to jam a        prior art mechanism. Wherein the drive mechanism can no longer        move the rod, causing a sensed system shut down or an equipment        breakdown as in a broken rod connector.    -   e. Chemical leakage into a solvent source such as a solvent        chamber found in a rear of a mixing module, reduces the        effectiveness of the solvent, and greatly reduces the life of        the mixing module.

III. Premature Wear of the Mixing Chamber

-   -   a. Most mixing modules are based on relatively tight tolerances        and fairly critical press fits. Thus, any tolerance deviation        caused by movements leakage, can lead to related failures.    -   b. If these fits are not held, the mixing chamber, will, in        addition to leaking, also, be subjected to damage due to motion        of the valving rod. The damage may not be noticeable to the eye,        but even microscopic deformations can have noticeable effects.    -   c. Any damage or wear to the Teflon mixing chamber will        exacerbate the leakage issues noted above.    -   d. Damage to the inside diameter surface of the mixing chamber        will also create fissures, crevices, and score marks that will        be nucleation sites for urethane buildup. Once the urethane        buildup gets started, it will attract more urethane to itself,        growing in size until it causes a mixing module failure.

The sequence of events is considered under the present invention to beas follows (although it is not the intention under the present inventionto be specifically bound or limited in any fashion in the beliefs (e.g.,analysis and conclusions) described herein in development of the presentapplication) with the explanation given relative to a typical prior artembodiment using Bellville washer compression:

-   -   1. The mixing module starts its life in aligned condition, with        the ports in the mixing chamber in good alignment with the        through holes in the mixing module housing. As the mixing module        is used, urethane naturally builds up on the inside diameter of        the mixing chamber.    -   2. The slow buildup of urethane on the inside diameter of the        mixing chamber gradually increases the sticking force between        the valving rod and the mixing chamber.    -   3. At some point, when the bond strength increases to a critical        level, the act of retracting the valving rod causes the mixing        chamber to move back into the Belleville washers that constrain        it from the rear. The stack of Belleville washers is in effect a        powerful spring with short travel.    -   4. The valving rod will move the chamber in the direction of        travel, which compresses the Belleville stack. This will        increase the force pushing the mixing chamber forward until the        urethane bond is broken between the mixing chamber and the        valving rod.    -   5. Once the bond is broken, the Belleville washer forces the        mixing chamber forward, to near its original position.    -   6. If all of this motion were “perfect”, the mixing chamber        would not rotate, and it would return to its original position.        However, the forces in this situation are considered not        perfectly balanced, and the mixing chamber tends to rotate as it        is pulled back, or as it seeks to return to its home position.    -   7. The mixing chamber tends to rotate a tiny amount with each        cycle. After a large number of cycles, the sum of these minute        rotations manifest as a significant change in the radial        position of the port inside the mixing chamber housing.    -   8. These stresses on the chamber also cause it to distort, which        may account for the port movement that is apparent in the axial        direction with respect to the housing flow holes.

An additional problem associated with the prior art is the difficulty togain access to the mixing chamber to correct any of the above notedproblems that arise. For example, as seen from FIGS. 3A and 3B, priorart mixing modules, have been assembled using clip rings on the back capor compression cap. In order to install the clip ring, the back cap isforced into the Belleville washer stack, an action that requires about200 lbf to accomplish. Thus, the prior art method of assembly requiresthe use of machines like arbor presses and some special holding andalignment fixtures to put the prior art mixing module together. Thistype of design is difficult to both assemble and disassemble, as theclip ring can be both difficult to install and to remove with the heavyloads involved.

An additional problem associated with the prior art designs featuring anintegrated front end cap of the housing is the tendency for the frontend cap to deform or bulge out due to the loads exerted by theBelleville washer stack on the mixing chamber and, in turn, on the frontend cap abutting the mixing chamber. The prior art front cap swaged ontothe housing design is not of particularly high strength and is subjectto deformation. This deformation can generate reliability problems andlead to problems as outlined above for when the mixing chamber shifts inposition.

The prior art designs also suffer from difficulty in assembly. Forexample, the typical assembly process includes inserting the mixingchamber from the back end and attempting to line up the chemical portsprior to adding the Bellville washers, compression cap and C-clip. Thisalignment can be difficult and even if properly achieved the activityassociated with locking the C-clip can easily result in misalignmentproblems. In such events, the user has to undergo a difficult C-clipremoval and alignment sequence. The difficult disassembly and assemblyalso renders prior art devices poorly suited for field repairs and fieldrebuilds, requiring, instead, return to a service facility and servicetechnician involvement.

An additional problem associated with the prior art design, is thedifficulty in properly filling the solvent chamber with solvent. If canbe an awkward and messy procedure to fill prior art mixing modules withsolvent. For example, under one prior art design the solvent has to bedispensed into the back of the mixing module, just prior to using anarbor press to compress the washers. In additional to spillage duringthis process it is difficult to know whether the mixing module issufficiently full of solvent (e.g., because the viscosity of mostsolvent relied upon is quite high at room temperature it is easy for airto become trapped in the mixing chamber, giving a false impression of afull solvent fill). Once assembled, a check of the solvent cannot bemade under the prior art design absent going through the difficultdissembling process. Considering that mixing module life is typicallyproportional to solvent quantity, the presence of trapped air and lowquantity solvent levels can seriously degrade the life of the mixingmodule.

Once assembled and the C-clip locked, the solvent inside can degrade ordegrade internal seals over time. Thus rendering the prior art designill suited for harsh climates and/or prolonged storage as often involvedwith military applications.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed at reducing or obviatingat least some of the aforementioned difficulties and problems associatedwith the prior art. That is, with the assistance of the forgoinginsights considered to have been gained, various problems have beenaddressed under the present invention including those related to theaforementioned movement of the mixing chamber, and, under one embodimentof the invention, a mixing chamber has been developed which comprises alocking device that prevents the mixing chamber from pulling back with avalving rod into the compression means (e.g., a stack of Bellevillewashers). Thus, under one embodiment of the present invention there isprovided locking means to prevent other than beneficial cold-flow mixingchamber material movement relative to its support housing or confinementmeans. By providing a mixing chamber with position locking means,relative to, for example, valve rod reciprocation, there is prevented orat least minimized any movement (preferably both axial or radialmovement precluded) of the mixing chamber of the present invention upona sticking relationship forming between the rod and mixing chamber whilethe rod is being pulled back into the compression means.

The locking means of the present invention preferably functions byutilizing the housing as a fixed base, which housing is itselfpreferably fixed in position relative to the dispenser (e.g., hand heldhousing or frame supporting mixing module assembly). A mechanicalinterengagement between the housing or mixing chamber confinement meansand the mixing chamber is preferred, as it provides for the locking andremoval of the mixing chamber when desired. The locking means ispreferably applied about the entire circumference or a significantpercentage (e.g., 30% or greater either continuously or in spacedseries) of the mixing chamber to provide a degree of equal retentionforce about a significant portion or the entire circumference orperiphery of the mixing chamber. For example, a preferred locking means(which also has the benefit of ease in manufacture and mixing moduleinsertion and removal), is an enlargement of the outside diameter of thedistal end of the mixing chamber to match an enlarged inside diameter ofthe mixing module housing. This “mushroom” configuration in the mixingchamber (e.g., an annular stepped protrusion in a Teflon cold flowmaterial block), is designed to withstand the forces inherent in thedispensing mechanism, and to prevent or at least minimize any tendencyfor the mixing chamber to move backwards or shift with the rod.

Additional embodiments for the locking means include a reversal of therelative extending or protruding and receiving or recessed lockingcomponents or a mixture of both techniques. Again, it is preferable tohave a continuous full periphery projection or significantly fullcircumferentially arranged protrusions directed at preventing themovement of the mixing chamber and undesirable cold flow distribution ofmixing chamber material while the mixing chamber is under compressionmeans compression. For example, in a reversed arrangement, the mixingchamber is provided with one or more reception areas receiving radiallyinwardly extending member(s) either formed in the housing itself such asan integral protrusion or an added locking extension or extensionsextending in from or through the housing (e.g., serially arranged pins,an annular ring or the like which are sufficiently circumferentiallylocated as to provide a consistency in locking force against the forceof the spring or compression means working against the locking means).The axial positioning of “reversed” or non-reversed mixing chambermovement prevention means of the present invention is set to have theprotrusion(s) engage a sufficient axial amount of the mixing chamber tolock the chamber in axial position during valve reciprocation. Thehousing protrusion(s) in the “reversed” embodiment or the housingreception area(s) in the non-reversed embodiment are either based on amonolithic housing design (e.g., single molded, machined or formed unit)or comprised of a plurality of assembled components (e.g., inserted pinmembers or compressible annular sleeve or clamp arrangement or aninserted cylindrical sleeve in the non-reversed embodiment to catch thedistal end of an axially intermediate mixing chamber protrusion).Accordingly, rather than or in addition to, the above noted mushroom orexpanded distal end (the end where there exits the free end of the rod)the locking means of the present invention can be positioned at anintermediate or opposite (proximal end), locking means position. As willbecame more apparent below (e.g., the description of the loading of amixing chamber under the new mixing module housing design from thehousing front end) the “non-reversed”, distal positioned “mushroom”embodiment is preferred.

The design of the preferred embodiment of the invention also features afront end cap and back cap that are releasably secured to respectiveopen ends of the mixing module housing. In a preferred embodiment, thereleasable securement is by way of threaded connections atrespective-ends of the housing such as an internal thread at thecompression end which is preferably the rear end under the presentinvention and an external thread at the front end with the front endpreferably being arranged for finger grip insertion and removal of afront cap and at the rear end a simple tool threading or unthreading ofthe back cap.

This front cap and rear cap attachment to a front and rear open endedhousing design allows for in field servicing and rebuilding. Also, underthe design of the present invention, the front cap can be manufacturedseparately from the housing and made of a robust construction andmaterial. Also, the design of the present invention provides for frontend loading and manipulation of the mixing chamber prior to front endcap securement which allows for accurate mixing chamber chemical portalignment with that of the housing prior to front end cap closure (whichcan take place after or before back cap securement but preferably beforethe back cap insertion with the back cap insertion being used in acompression cap sense preferably carried out as the final assembly step(except for, optional activity associated with the addition of solventthrough a solvent cap opening and securement of the solvent cap asdescribed immediately below)). Port pins or the like can be used tofacilitate position maintenance during the final assembly process.

The inclusion of a releasable and securable solvent cap and placementthereof on the housing provides for the benefit of solvent fillingtaking place after all other components of the mixing module are fullyassembled without the spillage problems associated with the prior artand the design makes it easier to properly fill the solvent chamber fromthe outset as there can more easily be avoided trapped air problems andmove easily carried out a monitoring of the solvent level after fullassembly.

Despite being a readily accessible solvent input design, solventcontainment is assured with the solvent cap with even added assuranceprovided when a seal such as an O-ring is positioned between the solventcap and housing threads which further avoids the potential for leakingduring shipping. Moreover, the ready access allows for prolonged storagefree of solvent and in-field filling at the time of desired usage. Also,when going from usage to a prolonged storage state the solvent can beeasily removed and then refilled at the time of reuse.

A preferred embodiment of the invention features a dispenser modulecomprising a housing, a fluid reception chamber received within thehousing and having a rod passageway formed therein and at least onechemical passage port in fluid passage communication with the rodpassageway, a rod received in the rod passageway, and locking means forpreventing fluid reception chamber adjustment in conjunction with areciprocation adjustment in position of the rod.

A preferred embodiment of the invention also features a dispenser modulein the form of a mixing module wherein the fluid reception chamber is amixing chamber receiving at least two different chemicals, is formed ofa cold flow block of material such as Teflon material, and has a throughhole formed therein to define the rod passageway. The mixing modulefurther includes compression means (e.g., a stack of Belleville washers)for imposing compressive forces on the mixing chamber and the rod isdimensioned relative to the mixing chamber such that, in use, despite arod to chamber sticking relationship being likely (assumed to occur atsome point during use) the mixing chamber retains a pre-stick positiondespite the design of the compression means being such that it isadjustable in configuration or position upon being subjected to thecompression.

In the dispenser module, the locking means preferably includes aprojection/recess arrangement or relationship formed between the housingand the mixing chamber and providing a generally consistent peripheralor circumferential locking force between the mixing module and housing.For example, the projection/recess relationship preferably includes anannular projection in one of the housing and mixing module, and areceiving recess formed in a corresponding one of said housing andmixing module. A preferred embodiment has the projection formed closerto a first end of the mixing chamber than a second end, and with firstend being a front discharge end of the mixing chamber. The projection ispreferably also formed at a forward most end portion of the mixingchamber. The compression means is also preferably designed to becontinuously in compression mode at all times when the mixing module isassembled.

A preferred embodiment has the mixing chamber with the projection andthe housing with the corresponding recess, and the projection extendingover at least a majority of a periphery of the mixing chamber, such asone extending continuously without interruption about the mixing chamberperiphery. An annular projection ring that extends over the entireperiphery of the mixing chamber from the forward most end rearward to alimited longitudinal degree is illustrative of a suitable configuration.Also the projection preferably extends radially outward from acylindrical main body of the mixing chamber with the projection and mainbody being formed as an integrated monolithic unit, and with the radialextension (both ends of diametrical extensions considered) preferablyrepresenting 5 to 25% of a maximum diameter of the mixing chamber, with10 to 15% being sufficient for most uses (with half those amount aboverepresenting the annular radial distance or one of the two extensionsalong a diameter for the circumferential flange.

In an alternate embodiment of the mixing module of the presentinvention, the mixing chamber has a projection that extends about aperipheral area of the mixing chamber and the projection includesmultiple projection members arranged about that peripheral area of themixing chamber.

The present invention also features a dispenser module wherein the rodis dimensioned to seal off an exit opening in the chemical port uponreciprocation of the rod past said exit opening, and wherein there areat least two radially extending chemical ports formed in the mixingchamber and the rod passageway is represented by an axial throughpassageway in a cold flow block of material forming the mixing chamber.Also, in a preferred embodiment the rod functions both as a valving rodand purging rod and the fluid reception chamber includes two chemicalinlet ports that open into the rod passageway for mixing when the rod isin a retracted state and the rod is dimensioned to seal off the chemicalinlet ports when in a non-retracted state.

The dispenser module preferably has two or more chemical mixing inletsformed in a main housing and further comprises, in a preferred axialseries, a housing back closure member, the compression means, the fluidreception chamber or mixing chamber formed of a cold flow material (andalso preferably having at least two chemical inlet ports opening intothe rod passageway), and a front closure member. The housing front andback closure members are preferably releasably fixed to the housing withthe housing having an open front end and an open rear end, and the frontand rear closure members being secured into or over those opening so asto are close off the housings front and rear openings. The front andrear closure members are preferably releasably secured through use of,for example, a threaded engagement with the housing. Also, the fluidreception chamber is preferably formed of Teflon cold flow material andincludes two chemical inlet ports which open into the rod passageway andwith the housing having chemical feed apertures aligned with thosechemical inlet ports.

A preferred embodiment of the invention also features a mixing modulefor a two chemical component dispenser system, comprising a housinghaving a reception cavity and front and rear ends, a mixing chamberformed of a cold flow material and received in the housing, and themixing chamber having first and second chemical ports and a rodpassageway formed therein, as well as a rod received in the rodpassageway, a compression device which is positioned within the housingin a compression relationship with the mixing chamber (preferablycontinuously), a front closure cap releasably secured to the front ofthe housing and having a chemical discharge cavity formed in the frontclosure cap, and a rear closure cap releasably secured to the rear ofthe housing and having a rod reception cavity formed in the rear closurecap. A “secured” relationship for this embodiment means able to retainrelative position based on inter engagement means such as threadsdespite external forces acting thereupon with the noted external forcesnot including any specifically designed removal external forces such asunthreading forces, but does include maintaining position despite thecontinuous axial force of the compression means on the ends directly orindirectly.

Preferably, at least one of the front and rear closure caps are inthreaded engagement with the housing, with a preferred embodiment havingeach of the front and rear closure caps releasably secured such as onewhere each is in threaded engagement with a respective end of thehousing. Preferably the front closure cap is secured to the housing soas to be hand removable without tools and wherein the rear closure caphas tool engagement means for facilitating tool removal of the rearclosure cap from the housing, or vice versa.

The mixing module of the noted embodiment has a mixing chamber thatincludes rod stick movement prevention means for preventing movement ofthe mixing chamber with the rod as a unit relative to the compressionmeans when the rod becomes stuck to the mixing chamber during operation.A preferred rod stick prevention means features male/female lockingmembers associate with the mixing chamber and/or housing and which arepositioned to preclude axial movement of the mixing chamber as a wholewithin the housing. Also, the male locking member can include an annularfront ring extension provided in the mixing chamber which is receivedwithin an annular female recessed section of a front region of thehousing which recessed section defines a locking wall relative to adirection of movement of the mixing chamber opposite to the direction ofcompressive action being imposed on the mixing chamber.

The housing also preferably includes a solvent fill port opening intothe housing and a threaded solvent port cover which is releasably fixedto the housing to facilitate solvent filling and removal. A seal memberis further provided to help seal off the solvent port opening inconjunction with the port cover.

The present invention further comprises a mixing module that includes ahousing, a mixing chamber formed of a cold flow material and having achemical inlet port and a rod passageway, and a rod received within themixing chamber as well as a set of Belleville washers within the housingand in a compression relationship with the mixing chamber, and with themixing chamber and the housing being in a male/female lockingrelationship such by way of an annular male projection on one of thehousing and mixing module and a corresponding female recess receivingthe male projection on an opposite one of the housing and mixing module.An example of a suitable male/female locking relationship includes themixing chamber having an enlarged forward end forming a male lockingmember, and the housing having a recess formed in a front end forreceiving the enlarged forward end of the mixing module. Furthermore,the mixing module of the present invention preferably features a housingthat has open front and rear ends and front and rear closure caps areprovided that are designed releasable securement (e.g., threads) them tothe housing.

The present invention also features a method of assembly a mixing modulethat includes inserting into a housing (i) compression means, (ii) areciprocating rod, (iii) a mixing chamber, with the latter receiving therod and being placed in a state of compression by the compression means,and releasably attaching to the open front and rear ends of the housingrespective front end and back caps with the front and back caps having arod passageway opening formed therein. The method further includesarranging for locking means locking between the mixing chamber and thehousing to prelude mixing chamber movement despite a rod stickrelationship between the rod and the mixing chamber. The method alsopreferably features assembling the device such that a forward face ofthe mixing chamber contacts on inner surface of the front cap and therear cap is threaded on after the front cap is inserted onto the frontend of the housing.

A preferred method further comprising providing solvent into a solventopening formed in the mixing module housing and plugging the openingwith a solvent opening plug cap. The preferred method featuring theinsertion of solvent (e.g., heated to above room temperature or above100° F. as in 130° F.) after both the front cap and rear cap or closedoff by a prior releasable attachment of the front end rear caps.

The present invention also includes a method of dispensing comprisingpreventing relative movement of a mixing chamber and the housingreceiving that mixing chamber despite a sticking together of a valvingrod reciprocating within the mixing chamber and despite the potentialfor movement of compression means compressing the mixing chamber were ifnot for the locking means, and with the compression means imposingcompressive forces continuously on the mixing chamber following assemblyand the locking forces being designed to avoid uneven applicationchamber relative to the periphery of the mixing.

BRIEF DESCRIPTION OF PREFERRED EMBODIMENTS

Many aspects of the invention can be better understood with reference tothe following drawings, with emphasis being placed upon illustrating theprinciples of the present invention. Moreover, in the drawings, likereference numerals designate corresponding parts throughout the severalviews.

FIG. 1 shows a two component, hand held prior art dispensing system fordispensing foam.

FIG. 2 provides an exploded view of the dispenser used in the system inFIG. 1.

FIG. 3A shows a cross-sectional view of a prior art mixing chambercartridge used in a hand held dispenser.

FIG. 3B shows a cross-sectional view taken along cross-section line3B-3B-III in FIG. 3A.

FIG. 4 shows a cross-sectional view of a mixing module of the presentinvention taken along cross-section line IV-IV in FIG. 5.

FIG. 5 shows a cross-sectional view of the mixing module of FIG. 4 takenalong cross-section line V-V in FIG. 4.

FIG. 5A is an enlarged view of the referenced front area of the mixingmodule shown in FIG. 5.

FIG. 6 provides a front end elevational view of the mixing module of thepresent invention.

FIG. 7 provides a cross-sectional view of the mixing module taken alongcross-section line VII-VII in FIG. 4.

FIGS. 8A and 8B provide different perspective views of the mixingchamber of the present invention.

FIG. 8C provides a partial front view illustration of a non-continuous,multi-protrusion locking means under the present invention

FIG. 8D provides a cut-away perspective illustration of the femalerecessed portion of the locking arrangement of FIG. 8C.

FIG. 9 provides a cross-sectional view of the mixing chamber of thepresent invention taken along cross-section line IX-IX in FIG. 11.

FIG. 10 shows a rear end elevational view of the mixing chamber in FIG.9.

FIG. 11 shows a cross-sectional view of the mixing chamber taken alongcross-section line XI-XI in FIG. 9.

FIG. 12 shows a cross-sectional view of the mixing chamber taken alongcross-section line XII-XII in FIG. 11.

FIG. 13 shows a cross-sectional view of the mixing chamber taken alongcross-section line XIII-XIII in FIG. 11.

FIG. 14 shows a top-front end perspective view of the mixing chamberhousing of the present invention.

FIG. 15 shows a top-rear end and side perspective view of the mixingmodule housing of the present invention.

FIG. 16 shows a bottom-side perspective view of the mixing modulehousing of the present invention.

FIG. 17 shows a cross-sectional view of the mixing module housing of thepresent invention taken along a vertical axis bisecting the illustrationin FIG. 14.

FIG. 18 shows a cross-sectional view of the mixing module housing of thepresent invention taken along a horizontal plane extending between edgesE1 and E2 of the housing and looking down.

FIG. 19 shows an interior or back side perspective view of the front capof the mixing module.

FIG. 20 shows an exterior or front side perspective view of the frontcap of the mixing module.

FIG. 21 shows a vertical bisecting cross-sectional view of the front capin FIG. 20.

FIG. 22 shows a cross-sectional view of the mixing module back cap takenalong cross-section line A-A in FIG. 24.

FIG. 23 shows a cross-sectional view of the mixing module back cap takenalong cross-section line E-E in FIG. 24.

FIG. 24 shows a perspective view of the mixing module back cap.

FIG. 25 shows a rear and side perspective view of the mixing module ofthe present invention.

FIG. 26 shows a front and top perspective view of the mixing module ofthe present invention.

FIG. 27 shows a front and side perspective view of the mixing modulespacer of the present invention.

FIG. 28 shows a rear and side perspective view of that spacer.

FIG. 29A-29G show in rotating side to top illustration sequence thechemical port of the present invention from a first originationviewpoint.

FIG. 30A-30G show a similar rotating illustration sequence of thechemical port from a second origination viewpoint.

FIG. 31A-31F show a rotating side to bottom illustration sequence of thechemical port.

FIG. 32A-32C show additional perspective views of the chemical port.

FIG. 33 shows a cross-sectional view of the chemical port taken alongcross section line F-F in FIG. 29A.

FIG. 34 shows a cross-sectional view of the chemical port taken alongcross-section line G-G in FIG. 30A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 4-7 illustrate mixing module 100 of the present invention whichcomprises housing 102 having a “front” (open) end 104 and a “rear”(open) end 106 with associated front end face cap 108 and back cap 110.Caps 108, 110 retain in operating position mixing chamber 112, slottedcup-shaped spacer 114 and Belleville washer stack 116 (the preferredform of compression means). Each of the face cap 108, mixing chamber112, spacer 114, washer stack 116 and back cap 110 have an axialpassageway for receiving valving and/or purge rod (“rod” hereafter) 118.Mixing module 100 also preferably has solvent chamber 122 with spacer114 and back cap 110 preferably formed with solvent reception pockets orcavities (123,124). The Belleville washers in stack 116 are also shownas having an annular clearance space (see FIGS. 5 and 7) whichfacilitates solvent flow or presence along the received portion of rod118.

As explained in greater detail below, solvent cap 126 is threadablysecured (or otherwise readably releasably secured with associatedtooling or hand gripping means as in a finger grip projection (notshown) or the more preferred tool insertion recess 216). Its seal offportion is fixable to housing 102 to close off solvent access opening128 formed in one of the sides of the multisided housing 102 (e.g., seethe FIG. 4 hexagonal wall arrangement). Solvent cap 126 is preferablypositioned to axially overlap part of the Belleville washer stack 116and the spacer 114 positioned between the compression means 116 andTeflon block mixing chamber 112. The Belleville washer stack 116 is alsopreferably arranged in opposing pairs (e.g., 8 washer pairs with eachpair set having oppositely facing washers) which provides a preferredforce level of for example, 150 to 250 lbf (with 200 lbf. beingpreferred for many uses of the invention) relative to spacer contactwith the mixing chamber and corresponding mixing chamber contact withthe interior face of front cap 108.

It should be noted that any dimension or range disclosure (includingthose above and below) presented in the present application is notintended to be limiting, but is provided for illustrative purposes tobetter appreciate a variety of aspects of the present invention.

As further shown in FIGS. 5 and 7, valving rod 118 has an aperturedreciprocating means capture end 130 (for example, a motorized rodreciprocator attachment end) and axially extends completely through thehousing and is shown to extend out past respective face and back caps108 and 110. Rod 118 also comprises annular limit ring 132 to avoid anunintended complete pulling out of rod 118 from the mixing module. A rodcontacting seal member 134 is further preferably provided such as aninserted O-ring into an O-ring reception cavity formed in back cap 110.Housing 102 is also shown in FIGS. 7 and 16 as including positioncavities 136, 138 for securing the housing in position relative to ahand held holder or a non-hand held dispenser system (e.g., baggersystem with fixed in position mixing module). It should be noted, thatwhile a preferred embodiment features the mixing module associated witha hand held dispenser the mixing module is not limited to hand helddispenser or foam-in-by systems, but is useable in any environment wherea mixing module is operated. As an example, reference is made to thefoam-in bag dispenser assembly and associated systems described inprovisional applications A-O listed in the Table below, and with each ofthe provisional applications listed being incorporated herein byreference.

REFERENCE U.S. SER. NO. FILED TITLE A 60/468,942 MAY 9, 2003 DISPENSERASSEMBLY WITH MIXING MODULE DESIGN B 60/469,034 MAY 9, 2003 BAGGER WITHINTEGRATED, INLINE CHEMICAL PUMPS C 60/469,035 MAY 9, 2003 MIXING MODULEDRIVE MECHANISM D 60/469,037 MAY 9, 2003 MIXING MODULE MOUNTING METHOD E60/469,038 MAY 9, 2003 DISPENSER TIP MANAGEMENT SYSTEM F 60/469,039 MAY9, 2003 HINGED FRONT ACCESS PANEL FOR BAG MODULE OF, FOR EXAMPLE, A FOAMIN BAG DISPENSER G 60/469,040 MAY 9, 2003 IMPROVED FILM UNWIND SYSTEMWITH HINGED SPINDLE AND ELECTRONIC CONTROL OF WEB TENSION H 60/469,042MAY 9, 2003 EXTERIOR CONFIGURATION OF A FOAM-IN- BAG DISPENSER ASSEMBLYI 60/468,988 MAY 9, 2003 BAG FORMING SYSTEM EDGE SEAL J 60/468,989 MAY9, 2003 IMPROVED HEATER WIRE K 60/468,982 MAY 9, 2003 FOAM-IN-BAGDISPENSER SYSTEM WITH INTERNET CONNECTION L 60/468,983 MAY 9, 2003ERGONOMICALLY IMPROVED PUSH BUTTONS M 60/488,010 JUL. 18, 2003 CONTROLSYSTEM FOR A FOAM-IN-BAG DISPENSER N 60/488,102 JUL. 18, 2003 A SYSTEMAND METHOD FOR PROVIDING REMOTE MONITORING OF A MANUFACTURING DEVICE O60/488,009 JUL. 18, 2003 PUSH BUTTONS AND CONTROL PANELS USING SAME

Housing 102 still further includes chemical passage inlet holes 140, 142formed for example, at midway points peripherally across side walls 144and 146 (FIG. 4) and within the forward axial half of housing 102 (e.g.,a location at about ⅓ back from the front end). Walls 144, 146 arepositioned to opposite sides of intermediate side wall 148 in thepreferred hexagonal configured housing 102. Wall 148 is preferablydiametrically opposed to wall 150 in which position cavities 136, 138are formed. Chemical inlets 140, 142 and they are shown positioned inthe preferred 120° chemical inlet spacing in walls 144, 146.

Reference is made to FIGS. 5A, 8A, 8B, 8C and 9-13, for a furtherdiscussion of mixing chamber 112 with locking or rod stick movementprevention means 158. FIGS. 8A and 8B provide perspective views of apreferred embodiment for mixing chamber 112 which is preferably formedof a low friction material such as one having cold flow capability withTEFLON brand material a preferred material.

Mixing chamber 112 has first end (e.g., spacer sleeve contact end) 152and second (e.g., front) end 154 which is placed in abutment with thesimilarly configured interior surface of the front cap once installed inhousing 102. As shown in FIGS. 12 and 13, axial rod passageway (orthrough hole) 156 extends along through the central axis of mixingchamber 112 so as to open out at the first and second ends.

FIGS. 12 and 13 illustrate the preferred configuration for passageway156 as being a continuous diameter passageway of diameter Da (a range of0.1 to 0.5 inch is illustrative of a suitable diameter range Da with0.15 to 0.3 inch being a more preferred sub-range and 0.187 inch being apreferred value for Da). FIGS. 8A and 8B further illustrate locking orrod stick movement prevention means 158 in the form of lockingprotrusion 158, which in a preferred embodiment is an annular protrusionhaving a forward edge 160 (FIG. 8A) coinciding with the outer radialedge of front face 154, and rear edge 162 defining an axial inner edgeof peripheral surface 164. Sloped surface 161 extending between readedge 163 and adjacent edge 163 provides a chamfered rear edge portion inlocking protrusion 158 which facilitates proper positioning within thehousing during assembly. Locking protrusion 158 is preferably integralwith main body portion 166 (e.g., entire mixing chamber formed as amonolithic body and also preferably of a common material as in Teflon).As illustrated, the radial interior edge of step down wall ring 168extends from the front region of the main body portion 166. Rear end 152of main body portion 166 also preferably features a chamfered peripheraledge 151 defined between the rearward most edge 153 and an adjacent edge155 to facilitate initial insertion of the mixing chamber 112 intohousing 102. The slope of chamfered edge 161 preferably is the same asthat as for chamfered edge 151.

Locking means 158 can take on a variety of configurations under thepresent invention (e.g., either peripherally continuous or interruptedwith common or different lengths/heights protrusion(s) about theperiphery of the mixing chamber) as well as a variety of axial extensionlengths and a variety of radial extension lengths (e.g., a radialdistance R (FIG. 13) between surface 164 and the forwardmost outer,exposed surface of main body 166 of 0.025 to 0.1 inches with 0.035 to0.05 inches being a suitable sub-value range). Length R includes acombination of wall 168 and chamfered edge 161 with the latterrepresenting a small percentage of the radial distance R (e.g., slopedsurface 161 represents 25 to 50% of overall radial distance R). Theutilized axial length and radial extension of locking protrusion 158 isdesigned to provide a sufficient locking in position function (despiterod stick due to the static friction/adhesion relationship between therod and mixing chamber that can be expected during normal operation)with an efficient use of material.

FIGS. 8C and 8D provide a partial front view of the locking relationshipand a cut-away perspective view of the male protrusion component of themale/female multi-protrusion/recesses arrangement of an alternateembodiment of the locking means 158′ present invention. As seen therein,there is a non-continuous circumferentially serial mixing chamberprotrusion/recess set 159 for the locking means 158′ which is differentthan the male/female locking relationship of the first describecontinuous protrusion embodiment (dashed reference numbers correspondinggenerally with those in the first embodiment). FIGS. 8C and 8D furtherillustrate the housing intermeshing protrusion/recesses (167, 167′) set(female recesses 169 receiving male protrusions 191 in the illustratedembodiment) extending axially forward from a continuous backing wall168′ in mixing module 112′ and wall surface 190′ in housing 102′. Thecombination providing an axial stop in association with thecircumferential intermeshing as well as a rotation lock (although theaxial lock which precludes “axial rod stick” movement is considered allthat is required in practice).

FIGS. 5A, 8B and 12 illustrate the preferred continuous annularprotrusion locking means 158 featuring stepwall 168 extending off frommain body 166 (preferably with a curved filler or minor transition slopewall 170) with the overall locking protrusion diameter Dp beingpreferably of 0.25 to 1.0 inch with a preferred value of 0.56 of aninch. Diameter Dm of the rear end of main body 166 (FIG. 12) or averagewidth if there is other than a cylindrical cross-section for main body166 is preferably 0.35 to 0.75 inch or more preferably a value of 0.49of an inch with the difference (Dp−Dm=R) representing about 5 to 15% ofDp. Also, a preferred diameter Da for rod passageway 156 is 0.1 to 0.4inch or 0.15 to 0.3 inch as a preferred intermediate range with 0.19inch being a preferred value. The main body portion's radial annularwall thickness forming its annular ring (with its inner surface defingin the chemical mixing area) is preferably 0.1 to 0.5 inch with 0.15inch being preferred.

Also, while a two component system is a preferred embodiment of thepresent invention, the present invention is also suitable for use withsingle or more than two chemical component systems where there is apotential stick and compression means move problem in a mixing ordispensing chamber of a dispenser and a rod received therein.

Chemical port holes 174, 176 are shown in FIG. 8A, 8B and are formedthrough the radial thickness of main body portion 166 and are showncircumferentially spaced apart and lying on a common cross-section plane(a preferred arrangement as opposed to being axially offset). Thecentral axis of each port hole 174, 176 is designed to be in common witha respective central axis of inlet passage holes 140, 142 in housing 102(FIGS. 4, 5) and with each intersecting the central axis of passageway156.

Also, port holes 174, 176 each preferably have a step configuration withan outer large reception cavity 178 and a smaller interior cavity 180,and, therebetween, is formed annular step wall 181 with sloped orchamfered transition wall 179. The step configuration is dimensioned toaccommodate chemical ports 182, 184 (FIG. 4) which are preferablystainless steel ports designed to produce streams of chemicals that jetout from the ports to impinge at, for example, a 120° angle to avoidchemical cross-over problems in the mixing chamber cavity. As shown inFIGS. 4, 12 and 13, diameters Db and Dc are dimensioned in associationwith the dimensioning of ports 182, 184 with a preference to have theinlet end of ports 182 and 184 of a common diameter and aligned relativeto the exit end of housing inlets 140, 142. Ports 182, 184 are shown tohave an upstream conical infeed section and a cylindrical outfeedsection each representing about 50% of the port's axial length.Dimension Db is preferably from 0.1 to 0.3 inch, with 0.17 inch being arepresentative preferred value and dimension Dc is preferably from 0.05to 0.075 inch with 0.065 inch representing a preferred value.

FIG. 13 illustrates length dimension lines L1 to L4 for mixing chamber112 with L1 representing the full axial length of mixing chamber 112 orthe distance from the outer back edge to the forward most front edge(preferably 0.5 to 2 inches with 1 inch being a representative preferredvalue). L2 representing the axial distance from the back end 152 to theperipheral edge 160 of locking protrusion 158 (reduction from length L1being due to the inward slope (e.g., 5 to 15° from vertical with 10°preferred) of the mixing chamber's front face and with length L2preferably being 0.43 to 1.8 (or 0.02 to 0.07 inch smaller than lengthL1) with 0.95 (or 0.05 inch smaller than L1) being an illustrativepreferred value. L3 represents the axial length between the rear edge152 to locking protrusion interior edge 162 of surface 164 (preferably0.5 to 1.0 inch with 0.74 inch being a preferred value). L4 representsthe distance from the rear edge 152 to the central axis of the closestchemical passageway such as smaller interior cavity 180 (preferably 0.1to 0.3 inch with 0.18 inch being a preferred value).

FIGS. 5 and 5A illustrate front end 104 of mixing module housing 102having a larger diameter recess 186 which steps down to a lesserdiameter housing recess 188. FIG. 5A shows step up wall 190 formedbetween the larger and smaller diameter housing recess 186, 188 which isdimensioned to correspond with step down wall ring 168 of lockingprotrusion 158 to provide an axial movement prevention means relative toreciprocating rod 118. The abutting relationship establishes an axial nomovement locking relationship between mixing chamber 112 and housing 102when the mixing module is in an assembled state (see below) and withoutsuch movement there can be avoided both axial and rotational shifting inthe mixing chamber despite a temporary sticking of the rod in the mixingchamber and the potential for the compression means to compress were itnot for the locking means 158. Thus, the mixing chamber is not subjectto rod stick movement and avoids the previously mentioned problemsassociated with this movement, such as port misalignment.

The housing configuration is further illustrated in FIGS. 5, 5A, 7 and14-18, with the latter providing perspective and cross-sectional viewsof housing 102 alone. FIGS. 15 and 18 illustrate a preferred step upwall 190 configuration formed between large diameter recess 186 andinterior recess 188 which is radially transverse or oblique (e.g.,conically converging in a forward to rearward direction although aflush, non-oblique vertical wall contact relationship is preferred). Forexample, with reference to FIG. 18, housing 102 has a radial thicknessT1 defing recess diameter D1 at its forward most end (e.g., 0.10 to 0.20in (e.g., 0.15 in) for T1, and 0.5 to 0.75 in for D1 with D1 preferablyequal to 0.56, increases to thickness T2 of 0.2 to 0.3 in (0.25 inpreferred) with a common exterior circumference such that a reduceddiameter housing cavity 188 is formed which defines housing recessdiameter D2 (0.4 to 0.6 in with 0.49 preferred) and is bridged by stepwall 190. As best seen from FIG. 5A, step up wall 190 preferablycomprises a more axial forward abutment wall section 190′ followedaxially to the rear by a sloped wall section 190″. As shown, wallsection 190′ is more vertically oriented than wall section 190″, withwall section 190′ preferably extending transverse to the axial centerline of the housing 102. Wall section 190′ also preferably represents amajority or greater of the transverse length relative to wall section190′ with the axial run for wall section 190″ preferably being greaterthan its radial rise. The sloping wall 190″ provides for easierassertion of mixing module 112 (e.g., chamfer 151 to sloped surface 190″sliding while wall section 190′ is of sufficient radial length toperform the abutment/locking function). FIG. 5A also illustrates theexterior surface of main body being in sliding friction contact withsurface 188 of housing 102.

Rearward of the recess 188 defining housing surface there is provided aslight step up 194 (e.g., a 0.007 to 0.01 inch increase in going from D2to D3). With a preferred common exterior wall surface, the differentinterior diameters are formed by different wall thickness to T3 and T4and/or recess diameter differences. As seen from FIGS. 17 and 5 theminor step up 194 provides a forward limit for the Belleville stack,although spacer sleeve 124 preferably (in conjunction with the rear endcap 110) keeps the washer stack compressed and axially spaced fromstepdown 194. The expansion in going from cavity 188 to more rearwardcavity 193 also provides added radial clearance for accommodating theBelleville stack compression adjustments. Spacer 124 has an outerdiameter generally conforming to D2 and axially bridges step down 194.

As seen from FIG. 7, main body portion 166 of mixing chamber 112 ispreferably received entirely in housing recess 188 while Bellevillewasher stack 116 is received entirely in housing recess 193 defined bythickness T4. Spacer 124 preferably extends to opposite sides of step194, and at the rearward end of housing 102 there is preferably providedback cap reception recess 192 of diameter (e.g., 0.5 to 0.6 in with 0.50in being preferred) and thickness T5 (e.g., 0.2 to 0.3 in with 0.28being preferred).

Recess 198 is designed in receive back cap 110, with cap 110 isdimensioned to occupy the area of recess 198 and extend inward intorecess 186 and into contact with compression means 116. In this regardreference is made to FIG. 7 wherein L5 illustrates the axial length fromthe rear end of the housing into the rear end of compression means (inan assembled but non-operating state) 116 (e.g., 0.3 to 0.6 in or 0.45in representing about 10 to 30% or more preferably 20% of the full axiallength of mixing module 100 with 0% being at the back end). L6illustrates the axial length from the rear end to the central axis ofthe solvent access opening 128 which also is preferably generallycommensurate with the forward end of the compression means 116 and therear end of spacer compression 114 (e.g., 0.9 to 1.4 inches or 40 to 60%with 50±5% being preferable with 0% again being the back end); L7represents the contact interface between the front end of spacer sleeveand rear end of the mixing chamber 112 (e.g., 1.1 to 1.5 inches or 50 to65%); L8 (FIG. 5) representing the distance from the rear end 106 of thehousing and the central axis of housing inlet 140 (e.g., 1.3 to 1.9inches or 55 to 85%) and L9 representing the full axial length ofhousing 102.

Reception recess 192 includes means for axial locking in position backcap 110, which means is preferably one that allows back cap removalwithout the need for special support fixtures like an arbor press inreleasing the compression force and which can be tightened down by asimple tool to an operation location that compresses the compressionmeans to the desired force level. In a preferred embodiment a threadedrecess 192 is provided having relatively fine threads (e.g., 0.625-32UN-class 2B for the rear and somewhat coarser 0.750-32 UN-23 for thefront cap threads) for facilitating axially locking in position back cap110 at a desired compression inducing setting.

Housing 102 also preferably includes a further rearward (e.g., rearwardmost) end recess 195 that steps up into larger diameter D5 (e.g., a 0.02inch expansion) providing an annular sloping ridge 197 (facilitatingassembly of back cap 110).

As noted above, common prior art packaging foam mixing cartridges areassembled using clip rings on the back of a compression cap (see FIG.3). In order to install the clip ring, the back cap must be forced intothe Belleville washer stack, an action that requires about 200 lbf toaccomplish. This method of assembly of the prior art mixing cartridgesrequires the use of machines like arbor presses and some special holdingand alignment fixtures to put a mixing cartridge together making theprocess difficult. Also, assembly of prior art mixing cartridges likethat in FIG. 3 cannot be done by hand tools normally found in a toolkit. These prior art designs are difficult to assemble, and even moredifficult to disassemble, as the clip rings can be difficult to removewith the heavy spring load on the back cap.

In view of this, mixing module 100 of the present invention designed tobe easier to assemble and disassemble. Also, under the Belleville stackcompression forces imposed on prior art mixing chambers and mixingcartridges like that shown in FIG. 3, also tended to deform the frontface of the housing when considering the desirability for thinnessrelative to purge rod front face passageway travel. This deformation canoccur in prior art assemblies even after only moderate usage in thefield. That is, the front cover of prior art mixing chambers are oftenswaged onto the housing and the design is not always strong enough tofully handle the loads imposed without deflecting. This deformation cancause a number of reliability problems for the mixing cartridge.

A preferred embodiment of the present invention includes the feature ofhaving non-permanent, releasable securement means, with a preferredembodiment featuring threads (TH represents threads throughout theFigures and with MTH representing a meshing thread indication) providedon back cap reception recess 198 or some other releasable fixation meansas in, for example, a key/slot engagement. The threads of the back capreception recess are designed to mate with threads on the back cap 110while front end housing threads are designed for threaded engagementwith the front cap. Thus, a similar releasable securement relationshipis provided at the front end as in the back end with a preferredembodiment featuring threads provided on, for example, the exteriorsurface 200 at the front end of housing 102 for threaded engagement withinternal threads of face cap 102 (See FIGS. 19-21). This relationship atboth the front and back of the mixing chamber allows a mechanic ofminimal skills, without special fixture or exotic tools, to assemble anddisassemble mixing module 100.

The assembly technique under the present invention “releasablesecurement” (e.g., threaded construction) also has a variety of otheradvantages. For example, the securement construction is much easier toassemble without the clip ring that holds the back cap in place againstthe pressure of the Belleville stack. The present invention alsoprovides for easier field disassembly (e.g., a current foam productionsetting) as the securement construction makes it easier to rework orrebuilding at the foam production location without sending out to aspecial service location with special fixtures and the like for reworkor rebuilding.

The present invention helps avoid this prior art tendency for the frontcap of the housing to deform, or bulge due to the force imposed by theBelleville washer stack on the mixing chamber front face relative tosloped front face 154 being in contact with the interior,correspondingly sloped surface 207 of front cap 108 and the front end104 of housing 102 being in contact with another (preferably transverseto cap central axial axis) wall section 209.

The manner of attachment and construction of front cap 108 on the frontend of housing 102 provides for a more solid construction of the frontcap. That is, because of the means for releasable connection, the frontcap can be designed so that it avoids distortion under load. The presentinvention is thus designed to avoid the aforementioned problemsassociated with swaged front end caps, including difficulty in propermixing chamber installation and alignment, strength parameters that aredifficult to predict, and a tendency for deformation under high load.The ease of assembly and disassembly of the mixing module design, of thepresent invention in the production setting, also makes for easyassembly and disassembly both in the field and at a separate servicelocation.

With the arrangement of the present invention, it is easier to installthe mixing chamber from the front, instead of from the rear of themixing module housing. In a preferred embodiment of the presentinvention featuring mixing chamber locking means 158 at the front end ofthe mixing chamber and a releasable securement face cap 108, there isprovided the advantage of being able to install a mixing chamber fromthe front of the mixing module housing as compared to the more difficultrear installation in the prior art housing design. For example, thefront loading potential makes it much easier to orient the ports in themixing chamber into correct alignment with the through holes in themixing module housing as compared to dropping a mixing chamber into andout of finger reach once released into the chamber.

Also, to facilitate the assembly and disassembly of the mixing module ofthe present invention, face cap 108 is preferably provided with acircumferential knurled surfacing for the preferred finger contact onlytightening into position and releases for access (the rear or back captightening providing the higher level load upon the final stages ofassembly.) In an alternate embodiment, diametrically opposing, smoothperipheral front cap surfaces for wrench contact and final tightening orreleasing as in situations where external forces make for easier removalwith a wrench or the like due to, for instance, hardened foam spillbuild up in the region.

FIGS. 19 to 21 provide three dimensional views of front or face cap 108without full threading TH shown for draftperson convenience. Front cap108 is shown to include interior threaded surface 109 which screws ontohousing 102 along threaded surface 111 provided an exposed surface 200and provides the front boundary for the mixing chamber. The hole 204 inthe center is the exit for the liquid mixture of reacting precursors andalso receives the forward most end of the valve rod when in its maximumforward state. As seen from FIGS. 5A, 8A and 13 the front face 206 ofmixing chamber 112 features a conical taper on its interior surface witha preferred slope of angle β (e.g., 5° to 15°) and preferably 10°. Thusthe edge 208 at the front end passageway 156 represents the most forwardportion of mixing chamber 112 and the front face slopes rearward up tothe forward most peripheral edge 160 of locking protrusion 158. Withreference to 5A and FIG. 19 there can be seen that taper 207 formed onthe inside surface of the mixing chamber face 154 matches the taper oninterior surface of the front face 206 of the mixing chamber 112(preferably upon initial contact but certainly after compression againstthat face by the compression means.) The taper in the front face of cap108, allows the thickness of the face cap 108 at the center hole to bereduced, without sacrificing structural integrity. It is desirable toreduce this thickness to reduce the bonding area for urethane, since theTeflon material of the mixing chamber 112 cannot extend there. Forexample, FIG. 5A shown sloping front cap having a thinnest portion 211at surface 204, an intermediate thickness section 289 due to the slopingwall at angle β and then the thicker outer region (preferably the axialthickness at surface 204 is 0.033 and the thickness at 211 is 0.027).

Face cap 108 is preferably made from stainless steel, and designed tominimize the deflection caused by the force generated by the Bellevillewasher on the mixing module. The tolerances on the face cap 108 and thehousing itself are preferably held to a relatively high tolerancestandard in comparison to what is possible with the swaged approach usedby the mixing chamber shown in FIG. 3. The hole in the center of thefront cap 108 is made corespendiaingly very concentric to the insidediameter of the housing, which means that the valving rod will bemaintained centered on the hole in the front cap 108.

As seen in FIGS. 5, 7 and 22-24, at the rear end of housing 102 there isprovided back cap 110. The compression cap or back cap 110 is screwedinto the back threaded recess 210 at rear end 106 of housing 102 (FIG.7), after all of the internal components are in place (although there isalso the potential to close the front cap at the lest stage since bothends are accessible). The through hole 212 extending along the centralaxis of back cap 110 has undercut seal groove 134 to receive rear endO-ring 214 to seal the solvent into the chamber as the valving rod 118cycles in and out.

FIGS. 22-24 further illustrate back cap 110 having two smaller blindholes 216, 218 on each side of the center of cap 110 which are used torotate the cap as it is being threaded into the back of the housing. Ina preferred embodiment, a spanner wrench (not shown) is provided forassembly and disassembly of the back cap relative to the housing. Thespanner wrench has a two pin engagement end of the correct spacing toengage the two holes 216, 218 and a rear holding handle. Compression cap208 compresses the Belleville washer stack as it is screwed into thehousing. This action generates the compressive loads on the mixingmodule and generally involves a fairly high level of torque, so thespanner wrench is made sturdy. As shown in FIG. 5 and FIG. 24, back cap110 has an interior cylindrical portion 217 sized for contact with therear end of the compression means. A larger diameter intermediatesection 219 is featured which is threaded for threaded attachment withcorresponding housing threaded section 221. Between the threaded section219 and interior portion 217 is an indented section 223. On the oppositeside of section 219, there is an annular recess 225.

FIGS. 25 and 26 provide a view of an assembled 100 mixing module thatshows the front cap 108, the back filler cap 110, the opposite ends ofrod 118, and housing inlets or port holes 140, and 142. FIG. 25 furthershows spanner wrench reception holes 216, 218 compression cap 110, and afull view of the capture loop 130 of rod 118, which is configured toattach to a ball screw used on existing hand held systems, althoughalternate designs such as an expanded cylindrical back end as describedin an embodiment in the aforementioned U.S. patent application Ser. No.10/623,858, filed on Jul. 22, 2003 and entitled Dispensing System andMethod of Manufacturing and Using Same With A Dispenser Tip Management,now U.S. Pat. No. 7,182,221, which is incorporated herein by reference,is also representative of an alternate means for engagement with themixing module of the present invention and with a suitably formedreciprocator. FIG. 25 also shows the two conical point position holes136, 138 that are used to locate the mixing module in the dispensermanifold of an existing hand held system sold by Omni Packaging Inc. ofOklahoma, USA.

FIG. 26 illustrates solvent filler cap 126 (with an integral seal 217 asshown in FIG. 7) which offers significant advantages over the olderdesigns in that it is easier to fill with solvent after assembly of themixing module. It can be an awkward and messy procedure to fill thechamber with solvent in prior art mixing module designs such as those inFIG. 3A with back end loading in that the solvent has to be dispensedinto the back of the mixing module, just prior to using an arbor pressto compress the Belleville washer sufficiently to install an insidediameter clip ring on the back of the housing. This is not an easy orclean procedure, and it is difficult to know how much solvent is stillinside after the job is done. A cross-section view of the solvent cap126 is seen in FIG. 7 which shows how the solvent chamber is formed bythe solvent recesses 122, 124, formed in the opposing back cap 110 andspacer sleeve 114, and the free space of housing 102 not occupied by thecompression means positioned in the solvent chamber and between thespacer and back cap.

Under the present invention, mixing module 100 can be assembled in itsentirely, and access to the solvent port it still made possible based onthe relative positional relationship between, for example, the threadedsolvent cap access port and the spacer sleeve's recessed areas(described below in greater detail). This ability to completely assemblemixing module 100 and then introduce the solvent via solvent cap 126 andthe coordinated solvent chamber positioning and solvent chamber formingcomponent portions are advantageous, for example, in allowing for easy,reliable and clean solvent filling to occur after the assembly is fullytogether. It is also easy to open the solvent cap for an initial checkas to the solvent level and/or, less preferably, the back cap can bereadily removed for a solvent check after the mixing module has beenfully assembled. In prior art systems, it is often the case that thereis significantly less solvent than originally thought to exist. Forexample, a solvent chamber may appear to be full after the initialfilling operation, but a significant quantity of air can be trapped inthe solvent chamber, as the viscosity of commonly used solvents can bequite high at room temperature to preclude a full fill under the priorart systems. To further help address this under fill problem there iscarried out the step of heating the solvent to around 130° F. (e.g.,above ambient as in 120-150° F.) before filling represents a preferredstep.

Thus, under the present invention with the large diameter (e.g., 0.3 to0.6 inch and preferably 0.425 inch) solvent access cap 126 (relative toa 2.3 inch housing length, for example), strategically positionedrelative to the solvent chamber to provide solvent chamber access means,complete filling of the chamber is made easy to achieve without the airbubbles or overflow problems associated with prior art solvent chambers.Because the threaded solvent access hole allows for easy filling, thereis less chance that air pockets will be trapped when the chamber issealed. Since mixing module life is proportional to solvent quantity,eliminating any trapped air in the solvent chamber can extend the lifeof the mixing module. An easy refill on the solvent chamber withoutspecial tools is possible through use of the threaded solvent filler cap126 as it can be readily removed with a small screwdriver applied toslot 216 anytime there is a desire to check conditions on the inside ofthe mixing module. The solvent chamber therefore can easily be refilledwith solvent, and the cap re-installed. As shown in FIG. 7, O-Ring seal217 is provided on the solvent cap to help in preventing solvent fromleaking including during shipping.

Also, less leakage means longer life, and the sealed cap can be openedand resealed multiple times with minimal degradation in seal quality.With the solvent access means of the present invention the mixing modulecan be initially built and assembled at a manufactory or assembly sitewithout solvent if long-term storage is required. There are applicationsthat require long-term storage of system mixing modules in warehousesand/or the placement of mixing modules in harsh climates. In thesesituations, mixing module solvent, and any elastomeric seals in contactwith the solvent, can degrade over time if pre-inserted at initialassembly. The present invention provides for either no solvent insertionat the time of assembly or ready access to replace the old solvent andseals after an extended period. This storage feature can be anadvantage, for example, in some military applications, as well as inother environments and/or storage needs.

Also, solvent cap 126 can be opened and resealed multiple times withminimal degradation in seal quality and the mixing module can also beprovided without solvent if long-term storage is required for use inthose applications that require long term storage of system partsincluding mixing modules, in warehouses or even in harsh climates. Priorart mixing chambers with contained solvent, and any elastomeric seals incontact with solvent, will degrade over time. Thus, the ability of thepresent invention for post-manufacturing solvent supply or emptying andthe refilling capability of the present invention makes the presentinvention advantageous for use in harsh environments or in prolongedstorage state in military applications.

FIGS. 27 and 28 provide different perspective views of spacer sleeve114, which includes solid cylindrical forward section 218 which isintegral with forward compression contact face 220 which is placed incontact with the mixing modules rear end, having valve rod receptionopening 224, and at its rear end 223 (or compression means contact end)there is provided one or more spacer slots 228 defined between spacers226. At least one spacer slots 228 is preferably aligned with solventhousing access opening(s) 128. In a preferred embodiment, there aremultiple spacers 226 (e.g., 3-10 with 6 preferred) separated byarch-slots 228 which provide ready access from solvent opening 128 intosolvent sleeve reception cavity 122. The size of the solvent opening 128(see above) and/or the dimensional circumferential width and axial depthof the spacer slots 228 are designed to provide solvent introductionaccess to solvent chamber. As spacer sleeve 114 is subjected to the loadof the compression means, spacer 226 (and the remaining surfaces aswell) and thus has a thickness and configuration designed to handle suchloads. In addition, the interior side edges 227, 729 of slots preferablydiverge from each other going radially inward.

FIGS. 29A to 34 provide a variety of views illustrating the geometry ofa preferred chemical inlet port (such as 182 and 184 shown in FIG. 4)designed to provide accurate chemical injection and to provide aconfiguration that coincides with the geometry of the receiving portholes 174, 176, the exterior surface of the mixing chamber, and themixing chamber surface of the mixing chamber cavity at the cross-sectionof the ports. FIGS. 29A to 29G provides rotation sequence (at 15° angleintervals) with a front elevational view in FIG. 29A and FIG. 29Gprovides a top plan view with a 90° rotation relative to an end view inaxial direction of elongation of the mixing chamber. FIG. 30A provides aview similar to FIG. 29A, but with the port having been rotated 45°along its central axis of elongation to the present a front elevationview of the port from an end view of the mixing chamber.

FIG. 33 provides a cross-sectional view of port 182 (or 184—each beingpreferably of the same configuration and formed of, for example, astainless steel) taken along cross-section line F-F in FIG. 30A. FIG. 34provides a cross-sectional view of port 182 taken along cross-sectionline G-G in FIG. 29A. FIG. 34 illustrates upwardly convex surface ofradius RA2 having a radius of curvature (e.g., 0.246) designed tocoincide with the radius of curvature of the exterior circumference ofmixing module 100 (e.g., which has a diameter of about 0.5 inches(+/−0.1)) so as to avoid any discontinuance in surface until coming tothe edge in 231 of conical port section 230 which has a depth H₁ ofabout 0.066 to 30 to 60% of H₂ (the maximum height of port 182 which ispreferably about 0.151 inch and more preferably about 40%). As seen fromthe various views upper annular rim 232 undergoes a rise and lowersequence in going from generally a first convex raised area or (e.g.quadrant) 234, first recessed concave area (e.g., quadrant) 236, secondconvex raised area (e.g., quadrant) 238 and second recessed concave area(e.g. quadrant) 240 with a smooth, continuous curvature in going fromone to the next along the entire annular rim.

A comparison of FIGS. 33 and 34, shows edging 231 lying essentiallymidway between the upper point of height H₃ (which is the maximum heightreached by the edging of conical section 230 which conforms to themaximum height of annular rim 232 and is preferably about 0.072 inch)and an upper point of height H5 (e.g., 0.058 inch) which is the minimumheight level of the annular rim. Height H4 is preferably about 0.079inch. As seen from a comparison of FIGS. 33 and 34, annular rim 232 goesfrom, horizontal orientation, to and gradually changes in orientationfrom, the horizontal to the slope down from a higher interior end to alower exterior end. Edge 231 of conical port section 230 has a maximuminlet diameter D of about 0.114 inch for example which conically (e.g.,angle B₂ of 25 to 35° slope and more preferably 30°) decreases down tothe cylindrical passageway diameter D₂ of about 0.03 inch, for example.The diameter of the passageway is preferably made as small as possibleto maximize output velocity with the limiting factor being the operatingpressure of the system and the pump capacity.

FIG. 33 shows conical port section 230 with concave conical edge portion242 having a compound curve configuration RA1 to match the mixingchamber configuration. FIGS. 33 and 34 and the perspective Figures suchas FIG. 31A show a rotation of port 182 (or 184) from a front elevationto bottom plan view showing the curving or sloping bottom annular rim242 of port 182. Upper annular rim 232 has a minimum width W1 of 0.02 to0.03 inch (or 0.025 inch preferred), for example, an enlarged width W2of 0.024 to 0.034 (0.029 preferred), for example, while bottom annularrim W3 of 0.016 to 0.026 inch (0.016 inch preferred) for example, withW3 being a horizontal orientation. In going from the orientation of FIG.33 to that of FIG. 34 featuring two sloping down rim sections 244, 246of angle A2 about 15° (±5°) preferably with height H7 (e.g., 0.005 inch)for the extension down from the uppermost edge of the outlet 235 of port182 to the lowermost edge of that outlet. As illustrated, the downstreamend of conical port section 230 opens into cylindrical passageway 233 atabout the transition from the larger head 239 to port extension 237.Between the sloped sections 244 and 246 is planar section 245 with theoutlet port extending entirely across planar section 245 and partiallyinto sloped section 244, 246 with the combination of flat surfacesrepresented by RA3.

It should be emphasized that the above-described embodiments of thepresent invention, particularly, any “preferred” embodiments, are merelypossible examples of implementations, merely set forth for a clearunderstanding of the principles of the invention. Many variations andmodifications may be made to the above-described embodiment(s) of theinvention without departing substantially from the spirit and principlesof the invention. All such modifications and variations are intended tobe included herein within the scope of this disclosure and the presentinvention and protected by the following claims.

What is claimed is:
 1. A fluid mixing module, comprising: a housing; amixing chamber formed of a cold flow material and having at least onefluid inlet port and a rod passageway; a rod received within said mixingchamber; and a compression device positioned within said housing and ina compressive relationship with said mixing chamber, wherein said mixingchamber and said housing have a male/female locking relationship thatgenerates a movement-suppressing pressing-force between male and femalemembers of the male/female locking relationship, at least during avalving rod retraction operation in the presence of a rod-stickrelationship, that prevents a rearward movement of said mixing chamberrelative to said housing during retraction of the rod from a moreforward position in said mixing chamber to a more rearward position,said housing has open front and rear ends and said mixing module furthercomprises front and rear closure caps releasably secured to saidhousing, and the compressive relationship of said compression devicewith said mixing chamber biases said mixing chamber toward said frontend.
 2. The mixing module of claim 1 wherein said male/female lockingrelationship includes an annular male projection on one of said housingand mixing chamber and a corresponding female recess receiving said maleprojection on an opposite one of said housing and mixing chamber.
 3. Themixing module of claim 1 wherein said mixing chamber has an enlargedforward end forming a male locking member and said housing has a recessformed in the front end for receiving said enlarged forward end of saidmixing chamber.
 4. The mixing module of claim 1 wherein each of saidfront and rear closure caps are threadably secured to said housing. 5.The mixing module of claim 4 further comprising a solvent access closurecap in threaded engagement with a wall of said housing.
 6. Apolyurethane foam dispenser, comprising: the fluid mixing module asrecited in claim 1; a dispenser body which receives said mixing module;and a rod adjustment device connected to said rod for forward andrearward adjustment of said rod within said mixing chamber.
 7. A fluidmixing module, comprising: a housing; a fluid mixing chamber formed of acold flow material and having a rod passageway and a pair of fluid inletports opening into said rod passageway; a valving rod received withinsaid mixing chamber and adjustable between a fluid inlet ports seal offmode and a fluid inlet ports free passage mode; and a compression devicepositioned within said housing for compressing the cold flow material ofsaid mixing chamber, wherein said mixing chamber and said housing amale/female locking have arrangement that generates amovement-suppressing pressing-force between male and female members ofthe male/female locking arrangement that, at least during a valving rodretraction operation in the presence of a rod-stick relationship,prevents adjustment of said mixing chamber back into said compressiondevice when said valving rod and mixing chamber temporarily jointogether in a dispensing operation, and a front cap provided at a fluiddischarge front end of said housing, said front cap having an interiorsurface in which a fluid discharge opening is formed, said housingcomprises a cavity in which said compression device is received, andsaid compression device biases the mixing chamber as to force a forwardend of said mixing chamber into compressive contact with the interiorsurface of said front cap.
 8. A method of assembling a mixing modulecomprising: inserting into a housing: (i) a compression device, (ii) areciprocating rod, and (iii) a mixing chamber, with the mixing chamberreceiving the reciprocating rod and being placed in a state ofcompression by the compression device; setting a male/female lockingarrangement between the mixing chamber and the housing that generates amovement-suppressing pressing-force between male and female members ofthe male/female locking arrangement, at least during a reciprocating rodretraction operation in the presence of a rod-stick relationship, topreclude a mixing chamber rearward movement despite the rod-stickrelationship between the reciprocating rod and the mixing chamber duringa pullback of said reciprocating rod relative to the mixing chamber; andreleasably securing a front cap and a rear cap to said housing, whereinthe state of compression of the mixing chamber by the compression deviceis one where the compression device presses the mixing chamber againstan inner surface of the front cap.
 9. The method of claim 8 furthercomprising inserting solvent into a solvent opening formed in thehousing and plugging the solvent opening with a solvent cap.
 10. Amethod of dispensing a foam material which has a chemical bondcharacteristic upon hardening, comprising: feeding fluid foam precursormaterial to a mixing chamber received within a housing of a dispenserwith said mixing chamber having at least one inlet for foam precursorand at least one outlet for foam precursor; adjusting a valving rodreceived in said mixing chamber from a fluid block position to a fluidrelease position, wherein said mixing chamber is biased in adispensing-outlet-direction of the dispenser, at least during a valvingrod retraction toward the fluid release position, by a predeterminedcompressive force from a compression device positioned within saidhousing, and during adjustment of the valving rod there is preventedmovement of the mixing chamber relative to said housing by way of amale-female lock relationship between said mixing chamber and housing,the lock relationship being sufficient to prevent a relative rearwardmovement between the mixing chamber and housing during valving rodretraction toward the fluid release position regardless of the presenceof a chemical bond between the valving rod and the mixing chamber thatis at least temporarily greater than the predetermined compressive forceof said compression device on said mixing chamber; and releasing foammaterial from the outlet of said mixing chamber.
 11. A fluid dispensermodule, comprising: a housing; a fluid reception chamber formed of acold flow material and provided within said housing and having a rodpassageway formed in the fluid reception chamber and at least one outletand one inlet port in fluid communication with said rod passageway, saidfluid reception chamber having an upstream end and a downstream endrelative to fluid flow out of the dispenser module, the upstream endbeing within the housing; a rod received in said rod passageway andadapted to travel forward and backward within the fluid receptionchamber; a compression device that generates a compressive force on theupstream end of said fluid reception chamber as to bias the fluidreception chamber in a downstream direction, wherein said fluidreception chamber has a male/female locking arrangement relative to saidhousing that generates a movement-suppressing pressing-force betweenmale and female members of the male/female locking arrangement, at leastduring a rod retraction operation in the presence of a rod-stickrelationship, which prevents the fluid reception chamber from rearwardadjustment in conjunction with an adjustment in position of said rodfrom a forward to rearward direction in the presence of a bondrelationship with said fluid reception chamber, a front cap is providedat a front fluid discharge end of said housing and having an interiorsurface in which a fluid discharge opening is formed, and said housingdefines a cavity in which said compression device is received, and saidcompression device biases a first end of the fluid reception chamber asto force a second end of the fluid reception chamber into compressivecontact with the interior surface of said front cap.
 12. The dispensermodule of claim 11 wherein said male/female locking arrangement includesan annular male projection and an annular female reception arrangementprovided between said fluid reception chamber and said housing.
 13. Thedispenser module of claim 11 wherein said male/female lockingarrangement includes a circumferentially continuous annular projectionin one of said housing and fluid reception chamber and a correspondingreceiving recess formed in the other of said housing and fluid receptionchamber.
 14. The dispenser module of claim 11 wherein said male/femalelocking arrangement includes a projection that is formed on said fluidreception chamber and is formed of a cold flow material together with acold flow material main body of said fluid reception chamber and saidprojection is positioned closer to a first end of said fluid receptionchamber than a second end.
 15. The dispenser module of claim 14 whereinsaid projection and main body are formed as an integrated, monolithicunit.
 16. The dispenser module of claim 15 wherein said first end is afront discharge end of said fluid reception chamber and wherein saidprojection is one of a circumferentially continuous projection or aplurality of circumferentially arranged projection extensions.
 17. Thedispenser module of claim 16 wherein said projection is formed at aforwardmost end portion of said fluid reception chamber.
 18. Thedispenser module of claim 11 wherein said male/female lockingarrangement includes an annular projection extending radially off a mainbody of said fluid reception chamber and said main body is formed of afluorinated hydrocarbon polymer material.
 19. The mixing module of claim1 wherein said compression device is received within a cavity formed insaid housing and is in a biasing relationship with a first end of saidmixing chamber, and said front closure cap is in contact with a second,opposite end of said mixing chamber.
 20. The mixing module of claim 19wherein the first end of the mixing chamber defines an entrance openingthat receives the rod and the second end defines a discharge outlet fordischarging fluid received in the mixing chamber.
 21. The mixing moduleof claim 1 wherein said front closure cap is secured to said housing ata discharge end of said housing, and said front closure cap has a fluiddischarge opening and an internal surface in which said fluid dischargeopening is formed, the internal surface of said front closure cap beingin compressive contact with a free end surface of the mixing chamber anda discharge outlet of the mixing chamber is formed in the free endsurface of the mixing chamber.
 22. The mixing module of claim 21 whereinthe internal surface of said front closure cap is oblique as to form athinner thickness region in an area surrounding the fluid dischargeopening, and the free end surface of the mixing chamber has an obliquesurface conforming to the oblique internal surface of the front closurecap.
 23. The mixing module of claim 1 wherein said rear closure cap isadjustably received at a rear, non-fluid discharge end of said housing,and extends internally within the housing into contact with thecompression device, such that adjustment of the closure cap will adjusta compression level of the compression device.
 24. The method of claim 8wherein a fluid discharge opening is formed in the inner surface of thefront cap, and the compression device presses a first end of the mixingchamber against the inner surface of the front cap by applying acompressive force to a second end of the mixing chamber opposite fromthe first end.
 25. The method of claim 8 wherein said rear cap isadjustably secured to a rear, non-fluid discharge end of the housingsuch that adjusting the rear cap will act to vary a compression level insaid compression device.
 26. The dispenser module of claim 11 furthercomprising a rear housing closure cap adjustably received at a rear,non-fluid discharge end of said housing, and which extends internallywithin the housing into contact with the compression device, such thatadjustment of the rear housing closure cap will adjust a compressionlevel of the compression device.
 27. The mixing module of claim 1wherein the compressive relationship of said compression device withsaid mixing chamber biases said mixing chamber toward said front end atleast during a retraction of the rod from a more forward position insaid mixing chamber to a more rearward position.
 28. The fluid mixingmodule of claim 7 wherein said compression device is configured to biasthe mixing chamber as to force the forward end of said mixing chamberinto compressive contact with the interior surface of said front cap, atleast during a valving rod retraction.
 29. The method of claim 8 whereinthe state of compression of the mixing chamber by the compression deviceis one where the compression device presses the mixing chamber againstan inner surface of the front cap at least during a pullback of saidreciprocating rod relative to the mixing chamber.
 30. The dispensermodule of claim 11 wherein said compression device biases the first endof the fluid reception chamber as to force the second end of the fluidreception chamber into compressive contact with the interior surface ofsaid front cap at least during an adjustment of said rod from a forwardto rearward direction.